Abstract:Triaxial creep test was carried out on marble samples from Jinping Hydropower Station under the condition of step unloading lateral stress and constant axial stress. The test process is introduced and the differences between axial and lateral creep properties are investigated. At the same time,the effect of stress state on the rheological properties of the marble is discussed;and the analysis shows that deviatoric stress is the main factor that affects creep deformation. By applying the Burgurs model as theoretical model to fit the processed creep curves,the parameters of the three-dimensional constitutive model are obtained directly. Based on comparison between the lateral and axial creep properties of the marble,obvious difference is found in the creep deformation law in the two directions;thus,it is unreasonable to propose a constitutive relation only based on the axial deformation. It is recommended that overall deformation property of the rock samples should be considered while proposing a three-dimensional constitutive model for marble from Jinping Hydropower Station.